The field of this invention involves hand held optical reading or scanning devices of the general type disclosed in U.S. Pat. No. 3,809,893 which issued to the assignee of the present invention. The optical reading device disclosed in this patent is of the form of an elongated generally cylindrical probe which is held like a pencil and incorporates optical fibers for transmitting reflected light to a photosensitive unit. Other similar optical reading devices are disclosed in U.S. Pat. Nos. 3,701,886 and 3,727,030. The prior art of hand held optical reading devices also includes devices which are adapted to be gripped in one hand, for example, such as the devices disclosed in U.S. Pat. Nos. 3,673,416, 3,685,723 and 3,947,817.